<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style type="text/css">
		*{
			padding: 0;
			margin: 0;
		}
		div{
			margin: 100px;
		}
		.user{
			font-size: 25px; 
		}
		.btn{
			position: relative;
			top: 3px;
			left: -5px;
		}

	</style>
</head>
<body>
	<!-- 微调我们元素位置-->

	<div>
		
		<input type="text" name="username"   class="user">
		<input type="button" name="" value="点我" class="btn">
	</div>
	
</body>
</html>